Field of the Invention
The present invention relates to a communication apparatus connectable to an external apparatus, and a control method thereof.
Description of the Related Art
There is known a digital camera which can be connected to a mobile phone via wireless communication and exchange image data with the mobile phone. There is also known a technique in which when establishing a connection by, for example, a wireless LAN (Local Area Network), communication parameters necessary for the connection are transmitted/received in advance by another wireless communication method, thereby automating some of user operations necessary for the connection by the wireless LAN. Japanese Patent Laid-Open No. 2013-157736 discloses a so-called handover technique of transmitting/receiving communication parameters necessary for communication by a wireless LAN by performing NFC (Near Field Communication) communication, establishing a wireless LAN connection, and transiting to the connection.
A digital camera may be connected to a data server (file server) used for an online storage service or the like by a communication unit such as a wireless LAN, and then data such as images in the digital camera may be transferred to the data server and backed up in it. As described in Japanese Patent Laid-Open No. 2013-157736, using the handover technique can automate some of user operations for establishing communication between the digital camera and the data server, thereby facilitating data transfer.
However, when data are transferred to a stationary external apparatus like a data server, the user performs no operation for the digital camera or data server during wireless LAN communication after a handover in many cases. Consequently, when the wireless LAN connection is interrupted or disconnected due to an abnormality such as a shortage of the remaining capacity of the battery of the digital camera, even if a notification of the interruption caused by some abnormality is sent, the user may not notice it. For example, if the user starts a backup operation, leaves there, returns after a given time, and then notices an interruption caused by an abnormality for the first time, the time until now is in vain. Therefore, it is desirable to notify, when performing near field wireless communication, the user of whether it is possible to perform data transfer (that is, data communication) after a handover. On the other hand, in data transfer with a mobile phone which is held by the user to perform an operation, the user can grasp the occurrence of an abnormality at any time. In consideration of the operability, it is desirable to complete handover processing within a time as short as possible.